The U.S. Department of Justice is examining bidders, including Apple and Google, interested in Nortel's patent portfolio, according to a report in the Wall Street Journal that cites unnamed people familiar with the situation.

The agency is worried that the patents could be used to hamper competition in the wireless industry, according to the report.

The DOJ has been reviewing Google's bid but hasn't found competitive issues with it, the Journal reported. However, companies including Apple and Nokia have been rumored to be planning to bid. According to the Journal story, the DOJ's antitrust division is concerned primarily with Apple and the company has been talking with the agency about the concerns.

When Google made its bid for the patents public, it said it wanted the portfolio to create a disincentive for others to sue Google.

Lawsuits are rife in the wireless market, which has experienced explosive growth. Many of the largest hardware and software makers are engaged in patent disputes. Companies that use Google's Android operating system have been popular targets.

Nortel has been selling off assets since it filed for bankruptcy protection in January 2009. It has sold its CDMA (Code-Division Multiple Access) wireless division to Ericsson for more than $1 billion and its enterprise networking business to Avaya for just under $1 billion.

The DOJ, which often does not comment on investigations, did not immediately reply to questions on Friday. Neither Google nor Apple replied to requests for comment.